To detect full-length genome of intron 19 of ARFGEF1 [intron19arfgef1]
Ontology highlight
ABSTRACT: Analysis of high-throughput transcriptome sequencing (RNA-seq) data often observed numerous 'non-co-linear' (NCL) transcripts, which may originate from genetic rearrangements (gene fusion) indicated the importance of fusion events and circRNAs in carcinogenesis; however, the role of ts-RNAs remains largely uninvestigated. Here we developed a hybrid sequencing pipeline ("NCLscan-hybrid"), which integrated different types of short (Illumina-based) and extra-long (PacBio-based) RNA-seq data to eliminate potential false positives from experimental artifacts, fusion events, and circRNAs. We applied NCLscan-hybrid to investigate of ts-RNAs in human breast cancer, the most malignant tumors diagnosed in women worldwide. Through multiple experimental validation steps, we confirmed that the intragenic ts-RNA, ts-ARFGEF1, was highly expressed in breast cancer cells but absent in normal breast cells. Furthermore, we experimentally validated that ts-ARGEF1 can contribute to cell proliferation and apoptosis. Analysis of xenograft in nude mice showed that disruption of ts-ARFGEF1 expression can significantly attenuate tumor growth. Microarray analysis revealed that ts-ARFGEF1 knockdown could trigger PERK/ATF4/CHOP signaling pathway, implying the function of ts-ARFGEF1 in ER homeostasis. Taken together, our findings provide an in-depth view of the true complexity of intragenic NCL events and, for the first time, show further insight into the potential roles of intragenic ts-RNAs in tumor cell development.
Project description:Analysis of high-throughput transcriptome sequencing (RNA-seq) data often observed numerous 'non-co-linear' (NCL) transcripts, which may originate from genetic rearrangements (gene fusion) indicated the importance of fusion events and circRNAs in carcinogenesis; however, the role of ts-RNAs remains largely uninvestigated. Here we developed a hybrid sequencing pipeline ("NCLscan-hybrid"), which integrated different types of short (Illumina-based) and extra-long (PacBio-based) RNA-seq data to eliminate potential false positives from experimental artifacts, fusion events, and circRNAs. We applied NCLscan-hybrid to investigate of ts-RNAs in human breast cancer, the most malignant tumors diagnosed in women worldwide. Through multiple experimental validation steps, we confirmed that the intragenic ts-RNA, ts-ARFGEF1, was highly expressed in breast cancer cells but absent in normal breast cells. Furthermore, we experimentally validated that ts-ARGEF1 can contribute to cell proliferation and apoptosis. Analysis of xenograft in nude mice showed that disruption of ts-ARFGEF1 expression can significantly attenuate tumor growth. Microarray analysis revealed that ts-ARFGEF1 knockdown could trigger PERK/ATF4/CHOP signaling pathway, implying the function of ts-ARFGEF1 in ER homeostasis. Taken together, our findings provide an in-depth view of the true complexity of intragenic NCL events and, for the first time, show further insight into the potential roles of intragenic ts-RNAs in tumor cell development.
Project description:Analysis of high-throughput transcriptome sequencing (RNA-seq) data often observed numerous 'non-co-linear' (NCL) transcripts, which may originate from genetic rearrangements (gene fusion) indicated the importance of fusion events and circRNAs in carcinogenesis; however, the role of ts-RNAs remains largely uninvestigated. Here we developed a hybrid sequencing pipeline ("NCLscan-hybrid"), which integrated different types of short (Illumina-based) and extra-long (PacBio-based) RNA-seq data to eliminate potential false positives from experimental artifacts, fusion events, and circRNAs. We applied NCLscan-hybrid to investigate of ts-RNAs in human breast cancer, the most malignant tumors diagnosed in women worldwide. Through multiple experimental validation steps, we confirmed that the intragenic ts-RNA, ts-ARFGEF1, was highly expressed in breast cancer cells but absent in normal breast cells. Furthermore, we experimentally validated that ts-ARGEF1 can contribute to cell proliferation and apoptosis. Analysis of xenograft in nude mice showed that disruption of ts-ARFGEF1 expression can significantly attenuate tumor growth. Microarray analysis revealed that ts-ARFGEF1 knockdown could trigger PERK/ATF4/CHOP signaling pathway, implying the function of ts-ARFGEF1 in ER homeostasis. Taken together, our findings provide an in-depth view of the true complexity of intragenic NCL events and, for the first time, show further insight into the potential roles of intragenic ts-RNAs in tumor cell development.
Project description:Purpose
The landscape of circular RNAs (circRNAs), an important class of non-coding RNAs that regulate gene expression, has never been described in human disorders of sex chromosome aneuploidies. We profiled circRNAs in Turner syndrome females (45,X;TS) and Klinefelter syndrome males (47,XXY; KS) to investigate how circRNAs respond to a missing or an extra X chromosome.
Methods
Samples of blood, muscle and fat were collected from individuals with TS (n = 33) and KS (n = 22) and from male (n = 16) and female (n = 44) controls. CircRNAs were identified using a combination of circRNA identification pipelines (CIRI2, CIRCexplorer2 and circRNA_finder).
Results
Differential expression of circRNAs was observed throughout the genome in TS and KS, in all tissues. The host-genes from which several of these circRNAs were derived, were associated with known phenotypic traits. Furthermore, several differentially expressed circRNAs had the potential to capture micro RNAs that targeted protein-coding genes with altered expression in TS and KS.
Conclusion
Sex chromosome aneuploidies introduce pervasive changes in the circRNA transcriptome, demonstrating that the genomic changes in these syndromes are more complex than hitherto thought. CircRNAs may help explain some of the genomic and phenotypic traits observed in these syndromes.
Project description:Numerous studies have described the altered expression and the causal role of miRNAs in human cancer. However, to date efforts to modulate miRNA levels for therapeutic purposes have been challenging to implement. Here, we find that Nucleolin (NCL), a major nucleolar protein, post-transcriptionally regulates the expression of a specific subset of miRNAs, including miR-21, miR-221, miR-222, and miR-103, causally involved in breast cancer initiation, progression and drug-resistance. We also show that NCL is commonly overexpressed in human breast tumors, and its expression correlates with that of NCL-dependent miRNAs. Finally, this study indicates that NCL-binding guanosine-rich aptamers affect the levels of NCL-dependent miRNAs and their target genes, reducing breast cancer cell aggressiveness, both in vitro and in vivo. These findings illuminate a path to novel therapeutic approaches based on NCL-targeting aptamers for the modulation of miRNA expression in the treatment of breast cancer. Identification of NCL regulated miRNAs by using miRNA high-throughput sequencing of HeLa cells stably expressing double-strand (ds) interfering RNA against NCL or scrambled sequences (sh-NCL or sh-Scr).
Project description:Circular RNAs (circRNAs) are a large class of animal RNAs. To investigate possible circRNA functions, it is important to understand circRNA biogenesis. Besides human Alu repeats, sequence features that promote exon circularization are largely unknown. We experimentally identified new circRNAs in C. elegans. Reverse complementary sequences between introns bracketing circRNAs were significantly enriched compared to linear controls. By scoring the presence of reverse complementary sequences in human introns we predicted and experimentally validated novel circRNAs. We show that introns bracketing circRNAs are highly enriched in RNA editing or hyper-editing events. Knockdown of the double-strand RNA editing ADAR1 enzyme significantly and specifically up-regulated circRNA expression. Together, our data support a model of animal circRNA biogenesis in which competing RNA:RNA interactions of introns form larger structures which promote circularization of embedded exons, while ADAR1 antagonizes circRNA expression by melting stems within these interactions. Thus, we assign a new function to ADAR1. Examination of 12 samples in different stages of C.elegans development.
Project description:Numerous studies have described the altered expression and the causal role of miRNAs in human cancer. However, to date efforts to modulate miRNA levels for therapeutic purposes have been challenging to implement. Here, we find that Nucleolin (NCL), a major nucleolar protein, post-transcriptionally regulates the expression of a specific subset of miRNAs, including miR-21, miR-221, miR-222, and miR-103, causally involved in breast cancer initiation, progression and drug-resistance. We also show that NCL is commonly overexpressed in human breast tumors, and its expression correlates with that of NCL-dependent miRNAs. Finally, this study indicates that NCL-binding guanosine-rich aptamers affect the levels of NCL-dependent miRNAs and their target genes, reducing breast cancer cell aggressiveness, both in vitro and in vivo. These findings illuminate a path to novel therapeutic approaches based on NCL-targeting aptamers for the modulation of miRNA expression in the treatment of breast cancer. HeLa cells were transfected with the control or anti-nucleolin siRNA. After 72hours total RNA was collected and analyzed by NanoString.
Project description:Numerous studies have described the altered expression and the causal role of miRNAs in human cancer. However, to date efforts to modulate miRNA levels for therapeutic purposes have been challenging to implement. Here, we find that Nucleolin (NCL), a major nucleolar protein, post-transcriptionally regulates the expression of a specific subset of miRNAs, including miR-21, miR-221, miR-222, and miR-103, causally involved in breast cancer initiation, progression and drug-resistance. We also show that NCL is commonly overexpressed in human breast tumors, and its expression correlates with that of NCL-dependent miRNAs. Finally, this study indicates that NCL-binding guanosine-rich aptamers affect the levels of NCL-dependent miRNAs and their target genes, reducing breast cancer cell aggressiveness, both in vitro and in vivo. These findings illuminate a path to novel therapeutic approaches based on NCL-targeting aptamers for the modulation of miRNA expression in the treatment of breast cancer. MCF7 cells were treated with the control drug or AS1411 aptamer. After 72hours total RNA was collected and analyzed by Affymetrix U133 plus.
Project description:This SuperSeries is composed of the following subset Series: GSE41971: In vivo NCL-targeting affects breast cancer aggressiveness through miRNA regulation [NanoString] GSE41972: In vivo NCL-targeting affects breast cancer aggressiveness through miRNA regulation [Affymetrix] Refer to individual Series